Telegram-like expressions panel

Currently expressions panel is too small. Resize feature somewhat helps but:

1. Its not convenient to click on the stickers button each time to open it
2. The placement is weird if show members is toggled on

Change the click action on a current stickers button to toggle the expressions panel in place of the members list. Hover action can be used instead to open the small version of the panel. This is how its done in Telegram.

That's pretty much it, you can check out how its done in telegram. I find it very convenient and would love to see that on fluxer.